The Joint Tactical Radio System (JTRS) was originally planned to be the next-generation voice-and-data radio to be used by the U.S. military in field operations after 2010. Launched with a Mission Needs Statement in 1997 and a subsequent requirements document in 1998 (which has been revised several times), JTRS was intended to be a software-defined radio that would work with many existing military and civilian radios.
A vital component of the JTRS program was the Ground Mobile Radio system (GMR), which was targeted for replacing the 2 existing Single Channel Ground and Airborne Radio System (SINCGARS) radios currently deployed on military vehicles with a 4 channel radio that could perform SINCGARS and also key “transformational” waveforms such as soldier radio waveform (SRW) and wideband networking waveform (WNW) that were currently in development. Key constraints on GMR were that it should not exceed the Size, Weight, and Power (SWaP) of the current SINCGAR radios, and that it should have a reasonable cost per channel.
Unfortunately, the JTRS program was been beset by delays and cost overruns, particularly the Ground Mobile Radios (GMR) unit. Problems included changing requirements and unexpected technical difficulties that increased the size and weight of the unit so that it did not meet its SWaP goals, and so that it became difficult to add the required waveforms and other capabilities. Current GMR radios will not fit on turreted vehicles and are too large and expensive to field. Overheating of units during field testing has been a frequent problem. As a result, in October of 2011 the US Army announced that it planned to cancel its contract for the Joint Tactical Radio System Ground Mobile Radio.
The United States government has invested hundreds of millions of dollars in the Ground Mobile Radio (GMR). The most significant investments have been made in the Network Interface Unit (NIU) software and security architecture. Changing these would cause many years of delay in creating a new modular radio system.
What is needed, therefore, is a software-defined tactical mobile radio solution that will meet the goals of the JTRS, including the SWaP goals, while utilizing as much of the already-developed GMR hardware and software as possible, so as to capitalize on the investments that have already been made.